Highlights
- A platinum electrode modified with TiO2-Mn3O4 nanoparticles and chitosan detected glucose without any enzyme.
- The TiO2-Mn3O4 hybrid gave a faster electron-transfer rate and stronger anodic current than TiO2 or Mn3O4 alone.
- Sensitivity was 7.073 microamps per millimolar with a linear range of 0.01-0.1 mM and a detection limit of 0.01 micromolar.
- The sensor was applied to estimate glucose concentration in real fruit samples including banana, strawberry, apple, grape, and pomegranate.
Abstract
This study reports a non-enzymatic electrochemical glucose sensor built by combining titanium dioxide (TiO2) and manganese oxide (Mn3O4) nanoparticles with a chitosan membrane on a platinum electrode. The TiO2-Mn3O4 hybrid catalyzed glucose oxidation without a glucose-oxidase enzyme, giving a higher anodic current and faster electron transfer than either oxide alone. The sensor showed a sensitivity of 7.073 microamps per millimolar across a linear range of 0.01-0.1 mM glucose, a detection limit of 0.01 micromolar, and stable, reproducible performance, and it was used to estimate glucose levels directly in fruit samples.
Research summary
Fruit consumption raises blood glucose levels, which is an important consideration for people managing diabetes. Most electrochemical glucose sensors rely on the enzyme glucose oxidase, which can be difficult to keep stable over time. This study developed a non-enzymatic glucose sensor by modifying a platinum electrode with a titanium dioxide-manganese oxide (TiO2-Mn3O4) nanocomposite and a chitosan membrane, and used it to estimate glucose levels directly in fruit samples.
What the study examined
- Fabrication of a Pt/TiO2-Mn3O4/chitosan electrode by combining TiO2 and Mn3O4 nanoparticles in a 1:1 ratio with a chitosan binder
- Comparison of the hybrid electrode’s electrochemical performance against electrodes modified with only TiO2 or only Mn3O4
- Sensitivity, linear range, detection limit, reproducibility, and stability of the glucose response using linear sweep voltammetry
- Selectivity against common interfering sugars, acids, and ions, and application of the sensor to estimate glucose in banana, strawberry, apple, grape, and pomegranate samples
Main findings
The TiO2-Mn3O4/chitosan electrode produced a stronger anodic current and a faster electron-transfer rate than electrodes made with TiO2 or Mn3O4 alone, indicating that the two oxides work together rather than simply adding their individual effects. The sensor’s current response increased linearly with glucose concentration from 0.01 to 0.1 mM, giving a sensitivity of 7.073 microamps per millimolar and a detection limit of 0.01 micromolar.
The electrode kept its response within about 2% when common food molecules and ions were present alongside glucose, and its signal decreased by only about 1.2% after 10 days, indicating good selectivity and stability. Using a calibration model built from these measurements, the researchers estimated glucose concentrations directly in the flesh of several fruit samples.
Why it matters
By replacing the glucose-oxidase enzyme with a stable metal-oxide nanocomposite, this approach points toward glucose sensors that could hold their calibration for longer and tolerate a wider range of handling conditions. Demonstrating the sensor directly on fruit samples also shows a practical route toward low-cost tools for estimating sugar content in food, alongside clinical glucose monitoring.
Citation
K. J. Babu, M. Sasya, N. Nesakumar, Prabakaran Shankar, M. B. Gumpu, B. L. Ramachandra, K. Arockia Jayalatha, J. B. B. Rayappan. Non-Enzymatic Detection of Glucose in Fruits Using TiO2-Mn3O4 Hybrid Nano Interface. Applied Nanoscience 7 (2017) 309-316.
